Load detector



May 10, 1960 R. E. EDMINSTER LOAD DETECTOR Filed May 22, 1957 United States P t fo F LOAD DETECTOR Robert E Edminster, St. Petersburg, Fla., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Application May 22, 1957, Serial No. 660,863

2 Claims. (Cl. 271-47) This invention relates to a device for detecting an overload condition and more particularly to a torque responsive type overload device particularly adapted for use with document transport apparatus.

Many forms of detector devices have been incorporated in document handling machines to detect jams caused by improper feeding of documents.

Usually these devices operate on the principle of the document crumpling in a restricted area and thereby raising a lever which operates electrical contacts or other mechanisms to stop the machine.

The subject device is designed for use in a transport system comprising driven belts which is not readily adaptable to the use of the usual contact operating devices. Instead, a jam produces an increased load on the belt transport system which, through the jam detector device, causes contacts to be operated to shut off the machine. In some instances this overload may represent only a small degree of increase over the normal load.

It is the principal object of this invention to provide an improved overload detector device having a high degree of sensitivity and by which a document jam is detected as an overload condition on a document transport system and is translated into a mechanical movement to stop the transport system.

Other objects of the invention will be pointed out in the follow description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is an elevation partly in section showing the overload detector device.

Fig. 2 is a vertical section taken on the trace 2-2 in Fig. 1.

Fig. 3 is a vertical section taken on the trace 3-3 in Fig. 2.

The subject torque responsive overload detector device is shown and described in U.S. patent application Serial No. 631,925, filed December 31, 1956,- on behalf of Robert E. Edminster et a1. Figs. 1, 2 and 3 listed above correspond to Figs. 8a, 8b and 8c, respectively of the above cited application and corresponding reference numbers are used there and herein.

Only so much of that machine as is necessary to the description of the jam detector device is shown and described herein. Reference may be made to the cited application for other details.

Referring to the figures, the overload detector drive is provided through a belt 160 and a pulley 162 rotatably mounted on a shaft 166. The output from the device is provided through the shaft 166 and a pulley 583 fixed thereto by a pin 583a and driving a belt 588. The overload detector is indicated at 182. The entire assembly is supported on a plate 10 by a bearing 188 attached thereto by screws 187 within which the shaft 166 is rotatably mounted.

The drive pulley 162, rotatably mounted on the shaft 2,936,172 Patented May 10, 1960 166, is fixed by pins 189 to a disc 190 also rotatable on the shaft 166. A disc 191 is fixed to the shaft 166 by a pin 192. The disc 190 and the disc 191 are connected by a spring 193 fixed to the disc 190 by a pin 194 and to the disc 191 by a pin 195. A spring member 196 in the form of a disc having three flexible fingers 196a, spaced about its periphery and inclined from the plane of the disc, is fixed to the disc 191 by screws 197 extending through the ends of the fingers 196a. Three pins 198, mounted at intervals of about the disc 190, extend through cutouts 199 similarly spaced in the disc 191. A stud 200a is mounted on one spring leaf of a pair of electrical contacts 200 mounted adjacent the jam detector unit for actuation in a manner described hereinafter. A cover member 201, having a hole 201a adapted to receive the stud 200a, is mounted on the disc 190, for example by screws (not shown), to cover parts of the jam detector unit. The jam detector unit is spaced from the plate 10 by a spacer member 202.

As described hereinbefore, the drive to the transport belt 588 is through the belt and the pulley 162 and through the disc pinned to the pulley 162. The pins 198 mounted on the disc 190 and projecting into the cutouts 199 in the disc 191, normally rest near one side of the cutout 199. The drive from the pulley 162 and disc 190 to the disc 191 is through the spring 193. Under normal load conditions the pins 198 rest near the counterclockwise edge of the corresponding cutouts 199 in the disc 191. However, when an excess load is applied to the belt 588 due to any excess of normal torque such as a check jam or a belt jam, the pulley 583 and the shaft 166 are retarded. The disc 191 carrying the spring 196 also is retarded. The effect of this retarding action is to shift the disc 191 counterclockwise relative to the disc 190 thereby causing the pins 198 to bear against the fingers 196a of the spring 196, and moving the center portion of the spring 196 to the left, as viewed in Fig. 1. The center portion of the spring 196 moves the stud 200a thereby opening the contacts 200. The contacts 200 may be connected in the energizing circuits of a transport drive motor to control motor shutoff when a jam condition is detected.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that various ornissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. An overload device comprising rotatable driving means, rotatable driven means, yielding means joining said rotatable means for transfer of load therebetween, elongated flexible means having one of its ends afiixed to one of said rotatable means and having the other of its ends extending therefrom in a substantially circular direction and in a direction inclined from the radial plane thereof, cam means extending from the other of said rotatable means and engaging said flexible means, the direction of incline of said flexible means and the direc tion of yielding of said joining means providing, in response to yielding of said joining means upon overload,.

yieldingly connecting said discs for the transfer of load I displacing said fiat member, and control means responsive to said displacement of said flat member.

References Cited in the file of this patent UNITED STATES PATENTS 1,180,651 Kimball Apr. 25, 1916 2,144,769 Melmer Jan. 24, 1939 2,313,888 Otis Mar. 16, 1943 2,689,891 Silver et a1. Sept. 21, 1954 2,696,581 Peterson Dec. 7, 1954 

